The present invention relates to a small-sized power relay and, more particularly, to a small-sized power relay used in combination with an electronic thermostat for automatic control of an air conditioner.
Conventionally, a temperature sensor of the thermostat employs Freon gas therein. The temperature difference needed by this type of temperature sensor for initiating switching on and off is 2.degree. to 3.degree. C. as measured in liquid. Nowadays, the gas type sensor is being replaced by an electronic type one which, in addition to being suitable for remote control, has the capacity to sense a temperature difference of 0.3.degree. C. as measured in liquid. However, a power relay for use in combination with the electronic type temperature sensor is needed to be effectively operative in response to the ultra-low signal current from the sensor.